Question:
Please specify your recommendations for provision of Indeed CM and EA/ESSO server resilience. Is it efficient to backup the servers and what components need to be backed up?
Please advise the best course of action in case of, say, server failure.

Answer:
The Indeed EA/ESSO and Indeed CM system store all the data (settings, licenses, authenticators, ESSO data, devices and policies) in the dedicated storage. 
In Indeed EA/ESSO, the storage is the Active Directory, for Indeed CM - it is either Active Directory or Microsoft SQL. 
We highly recommend to backup the storage first of all. With Active Directory, it is necessary to backup the Indeed Identity container and all of its sub-containers. With MS SQL, it is necessary to backup the whole of database. The backup copies can be created with any suitable software tool.

The Indeed EA/ESSO and CM server processes user requests and extracts/places data from/to the storage. No critical data is stored at the server, provided that encryption key files used to access the storage, reside at some protected storage, not at EA/ESSO/CM servers.

Thus, if a EA/ESSO/CM server fails, the users automatically switch to another available one. Moreover, you always can deploy a new server rather quickly.
For Indeed СМ, it is recommended to set up a cluster using Microsoft IIS. Then the users could make use of other servers using the same web service address.